The present invention relates to improved fastener constructions of the type having a curvilinear key-receiving groove therein.
By way of background, fasteners having curvilinear key-receiving grooves therein are well known. In the past, these grooves have been derived from a circular configuration. This limited the number of configurations which could be made, even though such different configurations were extremely numerous. In addition, in the past fasteners with grooved types of key-receiving configurations, insofar as known, contained only a single groove, which in certain circumstances limited the usefulness of the fasteners. In addition, in the past fasteners having groove-type of key-receiving configurations were based on a circular configuration and had sharp edges. These sharp edges rendered them susceptible to having counterfeit keys made from the grooves because the sharp edges facilitated the driving of a cylindrical member into the grooves. It is with addressing the foregoing aspects of the prior art that the present invention is concerned.